Important Preliminary Checks
Before Starting
Before using this section, perform the
Diagnostic System Check - Vehicle
in Vehicle DTC Information and verify all of the
following conditions:
• | The powertrain control module (PCM), malfunction indicator lamp (MIL),
and check engine are operating correctly. |
• | There are no diagnostic trouble codes (DTCs) stored. |
Verify the customer complaint, and locate the correct symptom in the table of
contents. Check the items indicated under that symptom.
Visual/Physical Check
Several of the symptom procedures call for a careful visual/physical check.
The importance of this step cannot be stressed strongly enough. This step can lead
to correcting a problem without further checks and can save valuable time. This check
should include:
• | PCM grounds for the following conditions: |
• | Vacuum hoses for the following conditions: |
• | Air leaks at the following components: |
- | Intake manifold sealing surfaces |
• | Wiring for the following conditions: |
• | Use the following tables when diagnosing a symptom complaint: |